Various electronic devices, including plasma processing tools used in the semiconductor industry, operate in the radio frequency (RF) band. In operation, these devices generate RF power. To effectively channel that RF power, information concerning its voltage, current, and phase are needed. While devices currently exist to measure the voltage, current, and phase in an RF system, they all suffer from one or more of the following drawbacks. First, these detectors have impedances which differ from the impedance in the transmission line. This results in poor readings due to reflections and power losses. Second, these detectors are typically large, cumbersome devices. Also, the designs are usually difficult to conveniently manufacture. Therefore, it is desirable to have a detector which avoids reflections and power losses due to impedance mismatching.